Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755243Ab3FGPAb (ORCPT ); Fri, 7 Jun 2013 11:00:31 -0400 Received: from 16.mo1.mail-out.ovh.net ([178.33.104.224]:41978 "EHLO mo1.mail-out.ovh.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753453Ab3FGPA3 (ORCPT ); Fri, 7 Jun 2013 11:00:29 -0400 X-Greylist: delayed 23077 seconds by postgrey-1.27 at vger.kernel.org; Fri, 07 Jun 2013 11:00:29 EDT From: Boris BREZILLON To: Mike Turquette , Jean-Christophe Plagniol-Villard , Nicolas Ferre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Boris BREZILLON X-Ovh-Mailout: 178.32.228.1 (mo1.mail-out.ovh.net) Subject: [RFC PATCH 04/50] ARM: at91: add PMC master clock Date: Fri, 7 Jun 2013 16:24:12 +0200 Message-Id: <1370615115-16979-5-git-send-email-b.brezillon@overkiz.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1370615115-16979-1-git-send-email-b.brezillon@overkiz.com> References: <1370615115-16979-1-git-send-email-b.brezillon@overkiz.com> X-Ovh-Tracer-Id: 17241186749816091676 X-Ovh-Remote: 80.245.18.66 () X-Ovh-Local: 213.186.33.20 (ns0.ovh.net) X-OVH-SPAMSTATE: OK X-OVH-SPAMSCORE: -100 X-OVH-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeeiiedrgedtucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd X-Spam-Check: DONE|U 0.5/N X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrfeeiiedrgedtucetufdoteggodetrfcurfhrohhfihhlvgemucfqggfjnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10402 Lines: 403 This is the at91 master clock implementation using common clk framework. The pll clock layout describe the MCKR register layout. There's four pll clock layouts: - at91rm9200 - at91sam9x5 Master clocks are given characteristics: - min/max clock output rate These characteristics are checked during rate change to avoid over/underclocking. These characteristics are described in atmel's SoC datasheet in "Electrical Characteristics" paragraph. Signed-off-by: Boris BREZILLON --- drivers/clk/at91/Makefile | 2 +- drivers/clk/at91/clk-master.c | 317 +++++++++++++++++++++++++++++++++++++++++ include/linux/clk/at91.h | 23 +++ 3 files changed, 341 insertions(+), 1 deletion(-) diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 564076f..d41f616 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -2,4 +2,4 @@ # Makefile for at91 specific clk # -obj-y += clk-main.o clk-pll.o clk-plldiv.o +obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o diff --git a/drivers/clk/at91/clk-master.c b/drivers/clk/at91/clk-master.c new file mode 100644 index 0000000..71ade7d --- /dev/null +++ b/drivers/clk/at91/clk-master.c @@ -0,0 +1,317 @@ +/* + * drivers/clk/at91/clk-master.c + * + * Copyright (C) 2013 Boris BREZILLON + * + * This masterram is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include +#include +#include +#include + +#define MASTER_SOURCE_MAX 4 + +#define to_clk_master(hw) container_of(hw, struct clk_master, hw) + +struct clk_master { + struct clk_hw hw; + struct clk_master_layout *layout; + struct clk_master_characteristics *characteristics; +}; + +static unsigned long clk_master_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u8 pres; + u8 div; + unsigned long rate = parent_rate; + struct clk_master *master = to_clk_master(hw); + struct clk_master_layout *layout = master->layout; + struct clk_master_characteristics *characteristics = + master->characteristics; + u32 tmp = at91_pmc_read(AT91_PMC_MCKR) & layout->mask; + + pres = (tmp >> layout->pres_shift) & 0x7; + div = (tmp >> 8) & 0x3; + + if (characteristics->have_div3_pres && pres == 7) + rate /= 3; + else + rate >>= pres; + + rate /= characteristics->divisors[div]; + + /* print overclocking or underclocking error */ + /* + if (rate < characteristics->output.min || + rate > characteristics->output.max) { + } + */ + return rate; +} + +static long clk_master_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + int mdiv; + int pres; + u32 div; + long best_rate = -EINVAL; + unsigned long best_diff = 0; + unsigned long cur_diff; + unsigned long pres_rate; + unsigned long cur_rate; + struct clk_master *master = to_clk_master(hw); + struct clk_master_characteristics *characteristics = + master->characteristics; + + if (rate < characteristics->output.min || + rate > characteristics->output.max) + return -EINVAL; + + for (pres = 0; pres < 7; pres++) { + if (pres < 7) + pres_rate = *parent_rate >> pres; + else { + if (!characteristics->have_div3_pres) + break; + pres_rate = *parent_rate / 3; + } + for (mdiv = 0; mdiv < 4; mdiv++) { + div = characteristics->divisors[mdiv]; + if (!div) + continue; + cur_rate = pres_rate / div; + if (rate < cur_rate) + cur_diff = cur_rate - rate; + else + cur_diff = rate - cur_rate; + + if (best_rate < 0 || cur_diff < best_diff) { + best_rate = cur_rate; + best_diff = cur_diff; + if (!best_diff) + return best_rate; + } + } + } + + return best_rate; +} + +static int clk_master_set_parent(struct clk_hw *hw, u8 index) +{ + u32 tmp; + if (index > AT91_PMC_CSS) + return -EINVAL; + tmp = at91_pmc_read(AT91_PMC_MCKR) & ~AT91_PMC_CSS; + tmp |= index; + + at91_pmc_write(AT91_PMC_MCKR, tmp); + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MCKRDY)) + ; + return 0; +} + +static u8 clk_master_get_parent(struct clk_hw *hw) +{ + return at91_pmc_read(AT91_PMC_MCKR) & AT91_PMC_CSS; +} + +static int clk_master_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int mdiv; + int pres; + u32 div; + u32 tmp; + unsigned long cur_rate; + unsigned long pres_rate; + struct clk_master *master = to_clk_master(hw); + struct clk_master_layout *layout = master->layout; + struct clk_master_characteristics *characteristics = + master->characteristics; + for (pres = 0; pres < 7; pres++) { + if (pres < 7) + pres_rate = parent_rate >> pres; + else { + if (!characteristics->have_div3_pres) + break; + pres_rate = parent_rate / 3; + } + for (mdiv = 0; mdiv < 4; mdiv++) { + div = characteristics->divisors[mdiv]; + if (!div) + continue; + cur_rate = pres_rate / div; + if (cur_rate == rate) { + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= layout->mask; + tmp &= ~AT91_PMC_CSS; + tmp |= pres << layout->pres_shift | mdiv << 8; + + at91_pmc_write(AT91_PMC_MCKR, tmp); + while (!(at91_pmc_read(AT91_PMC_SR) & + AT91_PMC_MCKRDY)) + ; + return 0; + } + } + } + + return -EINVAL; +} + +static const struct clk_ops master_ops = { + .recalc_rate = clk_master_recalc_rate, + .round_rate = clk_master_round_rate, + .get_parent = clk_master_get_parent, + .set_parent = clk_master_set_parent, + .set_rate = clk_master_set_rate, +}; + +struct clk * __init +at91_clk_register_master(const char *name, + int num_parents, + const char **parent_names, + struct clk_master_layout *layout, + struct clk_master_characteristics *characteristics) +{ + struct clk_master *master; + struct clk *clk = NULL; + struct clk_init_data init; + + master = kzalloc(sizeof(*master), GFP_KERNEL); + if (!master) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &master_ops; + init.parent_names = parent_names; + init.num_parents = num_parents; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + + master->hw.init = &init; + master->layout = layout; + master->characteristics = characteristics; + + clk = clk_register(NULL, &master->hw); + + if (IS_ERR(clk)) + kfree(master); + + return clk; +} + + +struct clk_master_layout at91rm9200_master_layout = { + .mask = 0x31F, + .pres_shift = 2, +}; + +struct clk_master_layout at91sam9x5_master_layout = { + .mask = 0x373, + .pres_shift = 4, +}; + + +#if defined(CONFIG_OF) +static struct clk_master_characteristics * __init +of_at91_clk_master_get_characteristics(struct device_node *np) +{ + int i; + u32 tmp; + struct clk_master_characteristics *characteristics = NULL; + + characteristics = kzalloc(sizeof(*characteristics), GFP_KERNEL); + if (!characteristics) + return NULL; + + if (of_property_read_u32_index(np, "output", 0, &tmp)) + goto out_free_characteristics; + + characteristics->output.min = tmp; + + if (of_property_read_u32_index(np, "output", 1, &tmp)) + goto out_free_characteristics; + + characteristics->output.max = tmp; + + for (i = 0; i < 4; i++) { + tmp = 0; + of_property_read_u32_index(np, "divisors", i, &tmp); + characteristics->divisors[i] = tmp; + } + + characteristics->have_div3_pres = + of_property_read_bool(np, "have-div3-pres"); + + return characteristics; + +out_free_characteristics: + kfree(characteristics); + return NULL; +} + +static void __init +of_at91_clk_master_setup(struct device_node *np, + struct clk_master_layout *layout) +{ + struct clk *clk; + int num_parents; + int i; + const char *parent_names[MASTER_SOURCE_MAX]; + const char *name = np->name; + struct clk_master_characteristics *characteristics; + + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (num_parents <= 0 || num_parents > MASTER_SOURCE_MAX) + return; + + for (i = 0; i < num_parents; ++i) { + parent_names[i] = of_clk_get_parent_name(np, i); + if (!parent_names[i]) + return; + } + + of_property_read_string(np, "clock-output-names", &name); + + characteristics = of_at91_clk_master_get_characteristics(np); + if (!characteristics) + return; + + clk = at91_clk_register_master(name, num_parents, parent_names, + layout, characteristics); + + if (IS_ERR(clk)) + goto out_free_characteristics; + + of_clk_add_provider(np, of_clk_src_simple_get, clk); + return; + +out_free_characteristics: + kfree(characteristics); +} + +static void __init of_at91rm9200_clk_master_setup(struct device_node *np) +{ + of_at91_clk_master_setup(np, &at91rm9200_master_layout); +} +CLK_OF_DECLARE(at91rm9200_clk_master, "atmel,at91rm9200-clk-master", + of_at91rm9200_clk_master_setup); + +static void __init of_at91sam9x5_clk_master_setup(struct device_node *np) +{ + of_at91_clk_master_setup(np, &at91sam9x5_master_layout); +} +CLK_OF_DECLARE(at91sam9x5_clk_master, "atmel,at91sam9x5-clk-master", + of_at91sam9x5_clk_master_setup); +#endif diff --git a/include/linux/clk/at91.h b/include/linux/clk/at91.h index 7ba038f..a960e2f 100644 --- a/include/linux/clk/at91.h +++ b/include/linux/clk/at91.h @@ -210,6 +210,17 @@ struct clk_pll_layout { u8 mul_shift; }; +struct clk_master_characteristics { + struct clk_range output; + u32 divisors[4]; + u8 have_div3_pres; +}; + +struct clk_master_layout { + u32 mask; + u8 pres_shift; +}; + struct clk * __init at91_clk_register_main(const char *name, @@ -233,4 +244,16 @@ at91_clk_register_pll(const char *name, const char *parent_name, u8 id, struct clk * __init at91_clk_register_plldiv(const char *name, const char *parent_name); + +extern struct clk_master_layout at91rm9200_master_layout; + +extern struct clk_master_layout at91sam9x5_master_layout; + +struct clk * __init +at91_clk_register_master(const char *name, int num_parents, + const char **parent_names, + struct clk_master_layout *layout, + struct clk_master_characteristics *characteristics); + + #endif -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/